I have recently noticed that an IR sensor stays on throughout even when my display is turned off. Also I have every possible settings turned off like attention awareness, face I’d, raise to wake etc. yet it remains same. I don’t know the reason but all I know is it serves no purpose to be on when the display is off. Please enlighten me!
[Edited by Moderator]
Original Title: iPhone 16 IR Sensor
iPhone 16
There is no documentation that the IR sensor can be turned off at all. Here is some information Apple has provided:
About Face ID advanced technology - Apple Support
The same question has been brought up before such as this one from 4 years ago. The comments then are basically the same that can be found here, as only Apple can answer "why" questions if they choose to do so. Apple has already made the statement that there is no concern from a safety standpoint.
Constant Infrared flashing - Apple Community
There is no documentation that the IR sensor can be turned off at all. Here is some information Apple has provided:
About Face ID advanced technology - Apple Support
The same question has been brought up before such as this one from 4 years ago. The comments then are basically the same that can be found here, as only Apple can answer "why" questions if they choose to do so. Apple has already made the statement that there is no concern from a safety standpoint.
Constant Infrared flashing - Apple Community
UPDATE: As per my observations, research, discussions, appointment with technician, I come to a conclusion that the IR EMITTER CAN’T BE TURNED OFF ENTIRELY (even when display is off). Yes that’s true, as per my observation even the iPhone 17 pro does that and I believe even the entire 16&17 lineup have this same behaviour. The exact reason for this behaviour is still uncertain but the final verdict is that ‘YOU CAN’T TURN IT OFF ENTIRELY’
You can turn off attention related features in Face ID but flood illuminator cannot be turned off entirely. There are other system processes that require attention. Several of these can be switched off such as Auto Brightness, but flood illuminator cannot be turned off entirely.
Any feature, service or app that accesses the True Depth camera may require the flood illuminator. So, yes you can disable Face ID and attention aware features. This usually reduces the frequency and length of time it’s needed, but it’s not possible to totally disable it.
Any AR or VR app or feature may require TrueDepth Camera, Camera functions such as Portrait mode, True Depth may activate as you move to touch the screen or pickup the device, and any interaction triggers.
You can try momentarily switching the attention features on and then off. This can resolve some glitches. Next step would be reset all settings. Please follow this path ,
iPhone > Settings > General > scroll down > Transfer or Reset iPhone > Reset > Reset All Settings
If that fails to resolve the issue please have Apple perform diagnostics on your iPhone. It can be done in person at an Apple Retail Store or at an Apple Authorized Service Provider. You can also contact Apple Support and request remote diagnostics.
If you’re in the US please call 1-800-MY-APPLE or outside the US, consult the support articles below. In Canada call 1-800-263-3394
Contact Apple for support and service - Apple Support
Genius Bar Reservation and Apple Support Options - Apple
Assuming that the posted arrangement image is correct (and I have ZERO reason to doubt it) …
… that source of emission appears to be the Flood Illuminator.
A brief session of online research points to this being a component of FaceID.
Please re-confirm thst you also disabled FaceID ?
Note that doing so would likely result in serious service and app functionality degradations; the specific impact would be depending on your exact setup.
(i.e. Impact to Apps and Services which are dependent on FaceID authentication)
Edit to add: Assuming that the image is of the “16” being discussed … what device (and which camera) is being used to capture the posted image?
Dn777 wrote:
So ultimately even you and apple don’t know why this emitter stays on when the display is off. Also I believe, I definitely don’t use any such apps that needs that emitter to be on all the time!
Apple? Yes, they would have the details and be able to determine if it is a bug as long as you send them the bug report using the feedback link or follow up with Apple Support directly where they can perform diagnostics and may even request log files. For us users, there is no supporting documentation that Apple provides and that is not unusual with many aspects of the inner workings of the OS and the device. All you can do is try, but if you are looking for an explanation of why, you may not find the answer you are looking for.
I think you’re correct. Because it’s an essential component of Face ID, along with the Dot Projector, flood illuminator might be active for any service the requires Face ID. This would include Apple Pay, Apple Wallet, accessing secure website, even opening a folder if its Face ID protected.
Apple is vague on every app, service etc. that may use True Depth camera. Your best opportunity will be to open a support ticket with Apple Support.
You need to have Apple perform diagnostics on your iPhone. It can be done in person at an Apple Retail Store or at an Apple Authorized Service Provider. You can also contact Apple Support and request remote diagnostics.
If you’re in the US please call 1-800-MY-APPLE or outside the US, consult the support articles below. In Canada call 1-800-263-3394
Contact Apple for support and service - Apple Support
Genius Bar Reservation and Apple Support Options - Apple
FWIW in my own - non-exhaustive - testing, that particular emitter renders on-screen as violet on both of the tested iPhone displays.
The test included:
Also noted was that the “selfie” camera seemed to be MUCH more sensitive to the emitter’s freq than the rear camera.
On both phones, the emitter is normally “off” and intermittently flashes for about 3 seconds when a FaceID authentication is initiated.
After the authentication fails, the emitter goes “dark.”
An emitter “continuously on” was never observed.
Just to confirm have you checked it with another camera (which can detect ir light) and the ir light stays on even when the display is turned off?
Here’s the order of cameras, sensors etc. on an iPhone 16.
It does look like you’re seeing the infrared camera. The IR camera doesn’t emit light, it records IR light. Specifically, the dot projector emits IR light and the IR camera records it.
IR light is red, hence the red in infrared. Cameras do not emit light , they record it. The white light you’re seeing is most likely the white light being reflected by the IR camera’s lens from the light you used to produce the photo.
You’re welcome to reach out to Apple Support for additional information. If you’re in the US please call 1-800-MY-APPLE or outside the US, consult the support articles below. In Canada call 1-800-263-3394
Contact Apple for support and service - Apple Support
I don’t know Apple knows and doesn’t know. If you believe your device is defective, open a support ticket. Escalate the issue through multiple tiers of support people and it might get escalated to engineering. However, they tend to be vague and they may not let you know the issue. However, they determine at some point if it’s a defect or performing a required operation.
I wonder if it’s not sort of like Schrõdinger’s cat. Your act of observing the light and recording it is the trigger.
Here is a basic spectrum showing the various wavelengths of light, including visible light.
Infrared light is invisible to the human eye because the rods and cones are not sensitive to infrared light. Infrared light doesn’t have an assigned color because we cannot see it. But as you can observe in the chart it’s above the red spectrum.
Please follow this path,
iPhone > Settings > Face ID & Passcode > enter passcode > Attention Aware Feature or Require Attention for Face ID, if they are enabled iPhone is checking for features before dimming display and for unlocking using Face ID.
Any manufacturers do comply with all required government regulations concerning health, safety etc. Grey areas are encountered when a corporation wants to protect trade secrets.
Here are a few articles,
About Face ID advanced technology - Apple Support
Legal - Data & Privacy - Apple
Biometric security - Apple Support
I doubt you will get much more out of senior support and/or engineering.
I can add the data gathered never leaves the iPhone. It’s encrypted and stored in the Secure Enclave, which has never been compromised. Enjoy.
IR sensor stays on when iPhone 16 display is off
